1. Field of the Invention
The present invention relates to an apparatus for driving a power seat of a vehicle, such as an automobile or a truck.
2. Description of Related Art
As a general rule, a seat attached to an automobile or a truck can be moved longitudinally to fit to the body of a person on the vehicle. In order to further improve the comfortability of the seat, some seats are arranged in such a manner that the height of the front portion and that of the rear portion of the seating portion can individually be adjusted. In this case, a suggestion has been made that electric motors are used to adjust the positions of the seat in the longitudinal direction and the height of the front portion of the seating portion and the rear portion of the same. The foregoing adjustments of the portions of the seat are inevitably performed by corresponding electric motors, each of which transmits power to the corresponding adjustment mechanism because the positions and directions to be adjusted differ from one another. However, the foregoing arrangement encounters undesirable increase in the number of elements, and therefore the structure becomes too complicated. What is worse, the overall size of the apparatus for moving the seat cannot be reduced. Accordingly, spaces for adding other functions to the seat cannot be obtained. Moreover, there arises a problem in that the assembling work becomes too complicated and takes a long time. Therefore, the overall cost cannot be reduced.